1. Field of the Invention
The invention relates generally to dispensing closures for dispensing containers of the type that are used to store and dispense viscous materials such as mustard and ketchup.
2. Description of the Related Technology
Containers that are used to store and dispense viscous foodstuffs and condiments such as ketchup and mustard employ a wide variety of closures in the United States and throughout the world. One commercially popular closure is shaped as a conical spout, and utilizes a twist-valve to open and close the dispensing passage. A second popular closure has a pivotally mounted snap-lid capable of being moved between a closed and an open dispensing position. In the closed position, the lid covers the dispensing opening and in the open position, the lid is moved away from the opening to allow the product in the container to be dispensed.
One problem that besets viscous foodstuffs such as ketchup and mustard is that thin liquid, e.g. the vinegar and aqueous base of the mixture, tends during periods of nonuse to form at the top of the container as suspended solids settle towards the bottom. When the container is inverted by a user to dispense the material, the thin liquid because of its initial position within the container and its lower viscosity will reach and be expelled from the closure opening before the more viscous material. Many consumers find this discharge of thin liquid to be unpleasant, and would rather not have it on their food. The thin liquid can also aerosolize as it is expelled from the closure and thus spray about in an uncontrolled manner that can make an unpleasant mess.
Consumers are advised to shake the container to mix the viscous material inside before dispensing, but this is often forgotten or avoided. Besides the unpleasant aspects of unmixed dispensing that are described above, premature depletion of the liquids from the suspension of the viscous material can lead to dehydration and thickening of the material.
A need exists for an improved system and method of dispensing viscous materials such as ketchup and mustard that reduces the potential for dribbling, spraying, mess-making and dehydration of the material as a result of early expulsion of the thin liquid component of the material during dispensing.